Pressing device

A pressing device, comprising:

• a circuit board comprising a first surface and a second surface opposite to each other, a through hole penetrating the first surface and the second surface, and an induction coil surrounding the through hole;
• a shaft lower cover comprising a lower cover base and a hollow shaft base protruding from the lower cover base, wherein the lower cover base is disposed on the first surface;
• a shaft upper cover disposed on the lower cover base and comprising an opening;
• and
• a movable shaft body movably disposed between the shaft upper cover and the shaft lower cover, and comprising a movable base and a columnar shaft protruding from the movable base, wherein the movable base partially protrudes from the opening, and the columnar shaft is connected to an induction member, wherein
• in response to the movable shaft body being pressed down, the columnar shaft extends into the hollow shaft base, and the induction member passes through the through hole, causing the induction coil to produce changes of induced current.